This fee covers any extra PreGender test you are ordering (or if we need) apart from two PreGender tests already ordered. This extra PreGender test is required after every six months because the difference between two cycles goes on changing by age. Also extra PreGender test is required when period is delayed by 4 days or more because that may be a temporary pregnancy or dissolved fetus. This sample will be compared with your previous two samples and will guide you accordingly. It will put you on right track to conceive the desired baby.